1. Field of the Invention
A subject of the present invention is a method for treating milk, preferably breast milk, in which the milk is briefly heated in a container, said method comprising the following steps:    the container is moved, preferably set in rotation, so that a milk film forms on its inner wall,    the milk is heated to a treatment temperature during a heating phase,    the milk is maintained at the treatment temperature for a treatment period of less than 20 seconds, and    the milk is cooled to room temperature.
Another subject of the present invention is a device for treating milk, preferably breast milk, in which the milk is briefly heated in a container, with an arrangement by which the container is held and moved, preferably rotated, with a heat source for heating the milk to a treatment temperature, and with a cold source for cooling the milk to room temperature.
2. Related Prior Art
A method and a device of the kind mentioned above are known from WO 00/74494 A2.
The known method and the known device are used to preserve milk, in particular breast milk, intended for storage or later use and/or to remove infectious microorganisms from the milk. Methods of this kind are generally known under the name pasteurization.
Feeding with breast milk not only offers infants, in particular preterm infants, advantages in terms of the feeding itself, but also has immunological advantages, since breast milk contains, in addition to protein, fat and carbohydrates, also many other constituents which ensure that breastfed children are less susceptible to infections and allergens than are children who have not been breastfed.
To avoid uncontrolled transmission of infectious diseases, the system of milk banks, in which breast milk from various donors was pooled, processed and then stored for later use, has now been abandoned. Therefore, in order to avoid infections, there is now once again a clear coordination between the infant and its own mother's breast milk.
However, for feeding preterm infants, this means that their own mother's breast milk has to be pumped off, processed and stored temporarily in the hospital and/or at home since, because of the immaturity and the low food intake capacity, and the frequent feeding associated therewith, these preterm infants cannot be breastfed. An additional factor is that preterm infants frequently remain three to four months in the hospital whereas the mothers are discharged only a short time after delivery, so that appropriate stocks of breast milk must be present in the hospital in order to ensure continuous feeding of the preterm infants. The technical significance of this is that even small volumes, for example of 20 ml, have to be processed and stored individually.
However, the known method and the known device are not just applicable for feeding infants, in particular preterm infants; they also have an application in the veterinary sector, for example in zoological gardens and for rare mammals.
The known device comprises two water baths into which a rotating round-bottom flask containing the milk to be treated is immersed in succession. At least in the immersed state, the round-bottom flask is set in rotation so that the milk forms a thin film on the inside wall of the round-bottom flask. The speed of rotation is about 300 rpm.
The rotating round-bottom flask is immersed for about 20 to 25 seconds into the first water bath which has been heated to 85 to 90° C., the temperature of the milk film rising to 68 to 70° C.
The still rotating round-bottom flask is then lifted from the first water bath and exposed for 5 seconds to the ambient air, the milk film reaching a target temperature of about 72° C. through delayed heating and heat exchange with the environment.
Thereafter, the still rotating round-bottom flask is immersed for about 20 seconds into a second water bath which is at a temperature of 2 to 4° C. After the round-bottom flask is lifted out of the second water bath, the breast milk again has a temperature of about 30° C. The entire inactivation cycle is completed after about one minute.
With the known device and the known method, it is possible to completely inactivate infectious microorganisms in the breast milk thus treated, but without denaturation of constituents of the milk taking place, and with most of the immunological properties of the milk being retained.
In this connection, the aforementioned WO 00/74494 A2 describes how in particular the cytomegalovirus (hereinafter CMV), which nowadays leads to the most common prenatal infections, can be completely inactivated by the known method and with the known device. However, other infectious microorganisms that may be present in breast milk can also be completely inactivated in this way.
The known method and the known device therefore have considerable advantages over two other treatment methods in which the inactivation is obtained either by heating for thirty minutes to 62.5° C. (Holder pasteurization) or by storing for many hours or even for several days at −20° C. (cryoinactivation). While cryoinactivation does not lead to complete inactivation of the infectious microorganisms, the activities of alkaline phosphatase and of lipase are much lower in Holder pasteurization than in the method described in WO 00/74494 A2.
However, lipase activity is particularly important for preterm infants, since it has been ascribed a key role in the absorption of fat in the preterm infant's intestine and has also been ascribed an important antiviral protective effect.
In the known method and in the known device, however, it is still considered to be a shortcoming that, compared to an untreated control, the lipase activity decreases by a factor of about two.